Add merge migrations to wagtailcore and wagtaildocs

We are not renumbering the collection migrations here, as some sites already exist
in the wild running a custom build of Wagtail 1.3 with collections, and we want
those to continue working.

wagtail/wagtailcore/migrations/0028_merge.py

@@ -0,0 +1,16 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.1 on 2016-02-03 13:50
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('wagtailcore', '0024_alter_page_content_type_on_delete_behaviour'),
+        ('wagtailcore', '0027_fix_collection_path_collation'),
+    ]
+
+    operations = [
+    ]

wagtail/wagtaildocs/migrations/0007_merge.py

@@ -0,0 +1,16 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.1 on 2016-01-28 14:46
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('wagtaildocs', '0005_alter_uploaded_by_user_on_delete_action'),
+        ('wagtaildocs', '0006_copy_document_permissions_to_collections'),
+    ]
+
+    operations = [
+    ]